import time
scale = 10
print("------执行开始------")
for i in range (scale + 1):
    a = "*"*i
    b = '*'*(scale - i)
    c = (i/scale) * 100
    print("{:^3.0f}%[{}->{}]".format(c,a,b))
    time.sleep(0.1)
print("------执行结束------")